It may be caused by the incompatibility with the new Kotlin plugin in your IDE.
We’ve added a warning to the docs: Redirect Notice
In Jmix Studio v.1.1.4 and below, the migration procedure may fail if your IntelliJ IDEA contains Kotlin plugin of a version newer than 1.5.10. In such a case, downgrade Kotlin plugin to 1.5.10 or below.
In Jmix Studio v.1.1.5 and above, the migration does not have a dependency on Kotlin plugin.